r.tile incorrect overlapping

[aardgoose]

r.tile using an overlap of 1 overlaps adjacent tiles by 2 columns, illustrated by the r.info extract below. Resolution is 32m and overlap S -N of is 64m.

+----------------------------------------------------------------------------+
 | Map:      TEXTZ-000-000@SK               Date: Tue Apr 26 11:52:03 2016    |
 | Title:    Tile 0,0 of SK32M ( TEXTZ-000-000 )                              |
 | Timestamp: none                                                            |
 |----------------------------------------------------------------------------|
 |                                                                            |
 |   Type of Map:  raster               Number of Categories: 0               |
 |   Data Type:    DCELL                                                      |
 |   Rows:         100                                                        |
 |   Columns:      100                                                        |
 |   Total Cells:  10000                                                      |
 |        Projection: Transverse Mercator                                     |
 |            N: 390031.98976328    S: 386833.0134357   Res: 31.98976328      |
 |            E: 403166.31130064    W: 399968.01705757   Res: 31.98294243     |
 |   Range of data:    min = 149.215669047674  max = 373.009547999747         |
 |                                                                            |
 |   Data Source:                                                             |
 |    SK32M                                                                   |
 |                                                                            |
 |                                                                            |
 |   Data Description:                                                        |
 |    generated by r.tile                                                     |
 |                                                                            |
 |   Comments:                                                                |
 |    r.tile --verbose input="SK32M" output="TEXTZ" width=98 height=98 ove\   |
 |    rlap=1                                                                  |
 |                                                                            |
 +----------------------------------------------------------------------------+

 +----------------------------------------------------------------------------+
 | Map:      TEXTZ-001-000@SK               Date: Tue Apr 26 11:52:03 2016    |
 | Title:    Tile 0,1 of SK32M ( TEXTZ-001-000 )                              |
 | Timestamp: none                                                            |
 |----------------------------------------------------------------------------|
 |                                                                            |
 |   Type of Map:  raster               Number of Categories: 0               |
 |   Data Type:    DCELL                                                      |
 |   Rows:         100                                                        |
 |   Columns:      100                                                        |
 |   Total Cells:  10000                                                      |
 |        Projection: Transverse Mercator                                     |
 |            N: 386896.99296225    S: 383698.01663468   Res: 31.98976328     |
 |            E: 403166.31130064    W: 399968.01705757   Res: 31.98294243     |
 |   Range of data:    min = 127.552440611917  max = 409.305838621671         |
 |                                                                            |
 |   Data Source:                                                             |
 |    SK32M                                                                   |
 |                                                                            |
 |                                                                            |
 |   Data Description:                                                        |
 |    generated by r.tile                                                     |
 |                                                                            |
 |   Comments:                                                                |
 |    r.tile --verbose input="SK32M" output="TEXTZ" width=98 height=98 ove\   |
 |    rlap=1                                                                  |